I think you are referring to what Chevy called the lower radiator grille baffle, shown as the lower part labeled "1.286 Baffle" in this picture. I think all of the inner sheetmetal, behind the grille, would have been black.
Curt ---- 1953 Chevy 6400, 1957 Chevy 2dr Sedan --"Mediocrity is easy, the good things take time"
